Key Concepts in Tree Diagrams
- Drawing tree diagrams
- Multiplying along branches
- Adding outcomes between branches
- With and without replacement
- Conditional probability from tree diagrams
Exam Tips for Tree Diagrams
- ๐กProbabilities along each set of branches must sum to 1
- ๐กMultiply along branches for "and" (both events occur)
- ๐กAdd results of different branches for "or" (either path leads to the outcome)
Exam Board Coverage
Tree Diagrams appears on all major GCSE Maths exam boards at both Foundation and Higher tier.
AQA
Edexcel
OCR
Frequently Asked Questions
What is the difference between with and without replacement?
With replacement: the item is put back, so probabilities stay the same for each draw. Without replacement: the item is not returned, so the total decreases and probabilities change.